Subsurface carbonaceous (e.g., coal) formations are geological formations below ground level that contain coal. Such formations are found throughout the world and are located at varying depths. Examples of subsurface coal formations are coal fields, coal reservoirs, coal basins, coal beds, coal seams, coal horizons, and coal mines.
Production of coal-bed methane (CBM) or other gas from subsurface coal formations involves injection of bioconversion microbes, nutrients for such microbes and/or chemical stimulants into the formations. However, the efficacy of existing injection techniques can be improved.
There is, therefore, a need in the art for improved injection of microbial, nutrient and/or chemical solutions into subsurface carbonaceous formations.